add toggle for testing cropped thumbnails

app/assets/stylesheets/specific/z_responsive.scss

@@ -101,13 +101,13 @@
       margin: 0 auto;
     }
     img {
-      object-fit: cover;
+      object-fit: contain;
       width: 48.5vw;
       height: 48.5vw;
       margin: 0 auto;
       border: none;
     }
-    img.cropped {
+    img.cropped-true {
       object-fit: cover;
     }
     &[data-tags~=animated]:before, &[data-file-ext=swf]:before, &[data-file-ext=webm]:before, &[data-file-ext=mp4]:before, &[data-file-ext=zip]:before {

app/logical/anonymous_user.rb

@@ -257,6 +257,10 @@ class AnonymousUser
     false
   end
 
+  def cropped_thumbnails?
+    false
+  end
+
   User::Roles.reject {|r| r == :anonymous}.each do |name|
     define_method("is_#{name}?") do
       false

app/models/user.rb

@@ -45,6 +45,7 @@ class User < ApplicationRecord
     is_super_voter
     disable_tagged_filenames
     enable_recent_searches
+    cropped_thumbnails
   )
 
   include Danbooru::HasBitFlags

app/presenters/post_presenter.rb

@@ -32,7 +32,7 @@ class PostPresenter < Presenter
       tag_param = nil
     end
     html << %{<a href="#{path}/#{post.id}#{tag_param}">}
-    html << %{<img itemprop="thumbnailUrl" src="#{post.preview_file_url}" alt="#{h(post.tag_string)}">}
+    html << %{<img class="cropped-#{CurrentUser.cropped_thumbnails?}" itemprop="thumbnailUrl" src="#{post.preview_file_url}" alt="#{h(post.tag_string)}">}
     html << %{</a>}
 
     if options[:pool]